Device and method for implenting dynamic adjustmenting bandwidth of data in a transmission device

ABSTRACT

A method and a device for realizing dynamic adjustment of data bandwidth of the invention are disclosed. The method comprises adding a control channel in a PCM trunk link to describe occupancy condition of time slots for current services. The device comprises a control word process circuit, a time slot distribution circuit and a CPU interface circuit, wherein the control word process circuit is designed to complete abstraction and insertion of control information in a control channel of E1/T1 link, the time slot distribution circuit completes separating voice time slots from Ethernet data time slots and rebuilding the data, and the CPU interface circuit implements time slot distribution control. The method and the device can implement dynamic adjustment of Ethernet data bandwidth while ensuring voice services, to make effective use of trunk bandwidth and enhance user&#39;s data service bandwidth, and there is no error code and interruption of data service during bandwidth adjustment.

FIELD OF THE INVENTION

The present invention relates to Ethernet communication technology, andmore particularly to a device and method for realizing dynamicadjustment of data bandwidth in a transmission device.

BACKGROUND OF THE INVENTION

Pulse Code Modulation (PCM), as a traditional concept, meansmultiplexing voice service to E1/T1 by PCM. With its development,particularly for demand for data services, PCM device is enhanced itscapability to support service. Now the concept of PCM is limited tomultiplexing voice, but can multiple services such as voice, data,image, etc. to E1/T1 on the basis of time slot, as shown in FIG. 1. Atthe beginning multiplexing data and image services is realized throughV.35 interface, and the device only simply maps V.35 channel to timeslot of E1/T1. It generally needs outside protocol converter or Routerfor realizing data service application with V.35 interface. Nowadays,for more conveniently and simply realizing access of data services forusers, many PCM equipments can supply 10M Ethernet interface to realizeseamless access of user data.

PCM devices have been widely used in telecommunication and specialnetwork, such as electric power, water conservancy and public securitybecause of its simply technology, flexible application and reasonableprice. However, in networking application with limited bandwidth,especially special net, it is generally required to sufficiently utilizethe trunk bandwidth because rental trunk bandwidth is limited.Particularly, when voice and data access mixed, it is required that dataservices can occupy idle time slots while voice is not activated.However, service bandwidth is generally configured in static state for aPCM device, and the bandwidth of data service is distributed to fixedtime slots. Even if voice service is free, data service cannot occupyidle bandwidth. If software is used to reconfigure numbers of time slotsfor data service by detecting idle time slots, it will result in buttingproblems with opposite equipments and error codes in data services evenservice interruption caused by changing bandwidth.

SUMMARY OF THE INVENTION

The present invention is to solve technical problems for overcomingshortcoming in IP and PSTN videophone of background technology, toprovide a method for realizing videophone terminal with transmitting IPaddress by PSTN and multimedia data information by IP network.

An object of the present invention is to provide a device, which canrealize dynamical adjustment bandwidth in a transmission equipment, inorder to dynamically adjust Ethernet data bandwidth and effectively userepeater bandwidth resources.

Another object of the present invention is to provide a method forrealizing dynamic adjustment of data bandwidth to dynamically adjustEthernet data bandwidth and effectively use trunk bandwidth resources,especially, to realize dynamic bandwidth adjustment for Ethernet data inthe intelligent integration PCM device in communication domain whileensuring voice services.

The method for realizing dynamic adjustment of Ethernet bandwidth in aPCM device according to the present invention comprises adding a controlchannel on PCM trunk link to describe time slots occupancy condition incurrent services (voice, Ethernet data, etc.). Application in peernetworking is required for realizing this method in order to realizecorrect demultiplexing and multiplexing for different services.

The difference between the present invention and traditional PCM voiceand data system is to offer a channel distribution mechanism. Themechanism, under control by a CPU, completes dynamic distribution oftime slots on a PCM line. It mainly comprises circuit configurations forcontrol word retrieving and insertion, time slot distribution and CPUinterface.

Time slot Distributing is controlled by channel control words written ina control channel, and the control channel may comprise one or more timeslots; however, one time slot is recommended to save occupancy of thecontrol channel in trunk data bandwidth.

Particularly, the present invention provides a method for realizingdynamic adjustment of data bandwidth in transmission equipment, in whicha control channel is added in trunk link in the transmission equipmentto describe time slot occupancy condition.

The control channel completes time slot dynamic distribution for PCMline under the control of CPU.

The time slot dynamic distribution is controlled by channel controlwords written in the control channel, and the control channel maycomprise one or more time slots.

The current services include voice service, Ethernet data service.

The method is applied in peer networking to realize correctlydemultiplexing and multiplexing different services.

The present invention also provides a device for realizing dynamicadjustment of data bandwidth in transmission equipment, which comprises:a control word process circuit, a time slot distribution circuit and aCPU interface circuit, wherein the control word process circuit isdesigned to complete abstraction and insertion of control information incontrol channel of E1/T1 link; the time slot distribution circuitcompletes separating voice time slots from Ethernet data time slots, andrebuilding data; CPU interface circuit is for implementing control ontime slot distribution.

The device also includes High Level Data link Control (HDLC)/MediaAccess Control (MAC) frame process circuit to implement processing HDLClink for Ethernet data, checking integrity of MAC frame, comparing andlearning MAC addresses.

The time slot dynamic distribution circuit is controlled by channelcontrol words written in the control channel, and the control channelmay comprise one or multiple time slots.

The present invention also provide a method for realizing dynamicadjustment of data bandwidth in transmission equipment, characterizedthat, when a current service is multiplexed to a direction of E1/T1link, CPU informs time slot distribution circuit of time slot numbers tobe occupied by the voice service according to voice call condition, andthe time slot distribution circuit releases the time slots from Ethernetdata service, and distributes to the voice service; after the voice callfinished, CPU informs time slot distribution circuit that the time slothas been released by the voice service, and time slot distributioncircuit assigns the time slots to Ethernet data service, thereby dynamicadjustment of Ethernet data service can be implemented.

The application of the present invention, compared with a prior art, canimplement dynamic adjustment of Ethernet data bandwidth while ensuringvoice services, and it reaches sufficient and effective usage of E1/T1trunk bandwidth without error codes and interruption of data serviceduring bandwidth adjustment, so that user's data service bandwidth isenhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic graph of integrated services multiplexed to E1/T1line;

FIG. 2 shows bit definitions of a control channel; and

FIG. 3 is a hardware schematic diagram of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with attached figures, embodiments of the technicalsolutions will be further described in details as follows:

A hardware portion of the present invention comprises a control wordprocess circuit, a time slot distribution circuit, a High Level Datalink Control (HDLC)/Media Access Control (MAC) frame process circuit anda CPU interface circuit. The control word process circuit implementsabstraction and insertion of control information in the control channelof E1 link, and the time slot distribution circuit implements separatingvoice time slot from Ethernet data time slot and rebuilding Ethernetdata, and the HDLC/MAC frame process circuit implements processing HDLClink for Ethernet data, checking integrity of MAC frame, comparing andlearning MAC addresses. The CPU interface circuit implements time slotdistribution control. Since circuit schematic diagrams in the preventinvention are known to those skilled in the art, and will not be furtherdescribed here.

A control channel is defined to locate in time slot 1 of E1/T1 link (time slot 0 is used as frame synchronization of link).

Bit definition of the control channel is shown as FIG. 2.

Channel segment number: taking values 0 to 5, representing occupancyinformation of 30 time slots with a channel bit table with 5 bits.

Channel bit table: representing data occupation condition of a time slot(2-30) with the channel sequence number. “1” expresses that the timeslot is occupied by Ethernet data, “0” expresses that the time slot isoccupied by the voice service.

According to above definitions, in each E1 frame (125 us), it needs toexpress condition on 30 channels, but, in each E1 frame, time slot 1 canonly express 8-bit information, so that it needs multiple E1 frames toexpress entire channel. A control word is made up of 3-bit time slotsegment numbers and 5-bit time slot bit tables. 30 time slots aredistributed in 6 time slot segments, and each time slot segment candescribe occupancy information of 5 time slots. To describe servicedistribution condition of 30 time slots demands 6 frames (6×125 us=1.5ms), and serial numbers of 6 frames are represented as time slot segmentnumbers. FIG. 4 lists time slot numbers expressed by control words in 6frames. TABLE 4 Control word configuration Time slot bit table Time slotsegment number Frame 1 TS2 TS3 TS4 TS5 TS6 0 0 1 Frame 2 TS7 TS8 TS9TS10 TS11 0 1 0 Frame 3 TS12 TS13 TS14 TS15 TS16 0 1 1 Frame 4 TS17 TS18TS19 TS20 TS21 1 0 0 Frame 5 TS22 TS23 TS24 TS25 TS26 1 0 1 Frame 6 TS27TS28 TS29 TS30 TS31 1 1 0

In the present invention the work quantity of software is smaller. InE1/T1 link to the direction of service demultiplexing, demultiplexingservice is completely implemented by hardwares without participation ofsoftware. When service is multiplexed to the direction of E1/T1 link(called direction of demultiplexing), CPU informs time slot distributioncircuit of time slot numbers to be occupied by the voice serviceaccording to voice call condition, and the time slot distributioncircuit releases the time slots from Ethernet data at latest 6 frames(1.5 ms) later and assigns to voice service; after the voice callfinishes, CPU informs time slot distribution circuit that the circuittime slot has been released by the voice service, and the time slotdistribution circuit assigns the time slots to Ethernet data service atlatest 6 frames (1.5 ms) later, so as to realize bandwidth dynamicadjustment of Ethernet data service.

1. A method for realizing dynamic adjustment of data bandwidth intransmission equipment, comprising adding a control channel in a trunklink of the transmission equipment for describing occupancy on timeslots by a current service.
 2. The method for realizing dynamicadjustment of data bandwidth in transmission equipment of claim 1,wherein the control channel implements dynamic distribution on timeslots in PCM line under control of CPU.
 3. The method for realizingdynamic adjustment of data bandwidth in transmission equipment of claim2, wherein the dynamic distribution on time slots is controlled bychannel control words written in the control channel, and the controlchannel comprises one or more time slots.
 4. The method for realizingdynamic adjustment of data bandwidth in transmission equipment of claim1, wherein the current service comprises voice service and data service.5. The method for realizing dynamic adjustment of data bandwidth intransmission equipment of claim 1, wherein the method is applied in peernetworking to realize correct demultiplexing and multiplexing ofdifferent services.
 6. A device for realizing dynamic adjustment of databandwidth in transmission equipment, comprising: a control word processcircuit, a time slot distribution circuit and a CPU interface circuit,wherein the control word process circuit is designed to completeabstraction and insertion of control information in control channel ofE1/T1 link; the time slot distribution circuit is designed to completeseparating voice time slots from Ethernet data time slots, andrebuilding data; the CPU interface circuit implements controlling ontime slot distribution.
 7. The device for realizing dynamic adjustmentof data bandwidth in transmission equipment of claim 6, wherein thedevice further comprises High Level Data Link Control (HDLC), MediaAccess Control (MAC) frame process circuit to implement processing HDLClink for Ethernet data, checking integrity of MAC frame, comparing andlearning MAC addresses.
 8. The device for realizing dynamic adjustmentof data bandwidth in transmission equipment of claim 6, wherein the timeslot dynamic distribution circuit is controlled by channel control wordswritten in a control channel, and the control channel comprises one ormore time slots.
 9. A method for realizing dynamic adjustment of databandwidth in transmission equipment, comprising: informing a time slotdistribution circuit by CPU of time slots numbers to be occupied by avoice service according to voice call condition when a current serviceis multiplexed to a direction of E1/T1 link; releasing the time slotsfrom data service by the time slot distribution circuit; anddistributing to the voice service; informing the time slot distributioncircuit by CPU of the time slot having been released by the voiceservice after voice call finishes; and distributing the time slots toEthernet data service by the time slot distribution circuit, thereby toimplement dynamic adjustment of Ethernet data service.